PhD Research Project: Predicting Genomic Effects on Structural Colour
Structural colours, caused by diffraction or interference of light from nano-scale structures, are some of the brightest and most impressive colours in nature. There has been extensive interest in replicating structural colours, which are produced from simple biological materials that are cheap and non-toxic, and can also have unique properties such as angle dependent colour (iridescence). However, very little is known about how the patterning of such fine structures is controlled in biological systems and the genetic pathways controlling this have yet to be identified in any system. We have performed crosses between subspecies of Heliconius butterflies that differ in iridescent structural colour and are using these to identify genetic loci underlying these differences. We also have genomic data from natural hybrid zones between these subspecies, which can be used to identify narrower genomic regions. This project would use this genomic data to predict how individual genetic loci control specific aspects of structural variation, and so fit within the area of “post-omic forecasting”. The project will involve computational modelling approaches, firstly to predict fine structural characteristics from small angle x-ray scattering data and secondly to predict this morphology from genotype
Nicola Nadeau has extensive experience of analysing genomic data to characterise patterns of divergence and gene-flow between species, as well as to identify genetic variants underlying phenotypic variation through approaches such as genome-wide association. She has authored several high profile publications identifying genetic variants underlying variation in colour and pattern in both butterflies and birds. This project would build on her NERC fellowship, using traditional genetic mapping approaches to identify the genetic architecture and loci underlying the convergent evolution of iridescent structural colour in two species of Heliconius butterfly. The biological aspect of this project would involve using existing genomic data from her lab, to identify genetic loci controlling specific aspects of fine structural variation.
Andrew Parnell is a physicist with a background in structural characterisation, using real space (scanning probe microscopy, optical) and reciprocal space scattering techniques (neutron and x-ray scattering). Throughout his career he has been interested in the dynamics of structure development in soft matter polymer and biological systems, with published and continuing studies to understand the nano-structuring and development of the structural colour elements of Jay feathers barbs and ultra white beetle scales. The physics element of this new project will involve using a combination of different precision structural techniques to correlate the differences in iridescent structural morphology with the underlying genetics responsible for their development. This will use scanning probe microscopy to directly image the local surface of the iridescent butterfly scales, alongside scanning electron microscopy for larger areas. These techniques give an overall picture of the diversity and variance in surface structure. We will then use ultra small angle x-ray scattering (USAXS), available to us at Sheffield via the recently installed Xenocs liquid gallium beamline, which will allow us to access the length scales relevant to structural colour in three dimensions. We also plan to use the high throughput facilities available to us via our successful and ongoing USAXS programme at the instrument ID02 (European Synchrotron Facility (ESRF)) to obtain structural data for all genotyped individuals.
How to apply: Go to http://www.sheffield.ac.uk/postgraduate/research/apply/applying after reading the information contained on that page click the link to the Postgraduate online application form
This project will be funded by the Leverhulme Trust Centre for Advanced Biological Modelling